Shovel loader



Sept. 20, 1949. E. A. DROTT ETAL SHOVEL LOADER 2 Sheets-Sheet 1 Filed Feb. 19, 1947 AT-roRNav P 1949- E. A. DROTT ETAL 2,482,612

SHOVEL LOADER Filed Feb. 19, 1947 2 Sheets-Sheet 2 lnven-roas 2M0. a. D417 W R. Du'q A'r-roaucv Patented Sept. 20,1949

UNITED STATES PATENT OFFICE SHOVEL LOADER Edward A. Drott and Edward R. prim, Milwaukee, Wis.

Application February 19, 1947, Serial No. 7 29,460

3 Claims. (01. 214-140) 1 The invention relates to loaders.

The general object of the invention is to provide a loader having new and improved hydraulically operated means for controlling the adjustment and movement of the bucket relative to the push beams on which the bucket is carried. More particularly, according to the present invention, the bucket is connected to its hydraulic tilting cylinder through a novel form of linkage connection which permits the loaded bucket to shift relatively to the push beams as they are raised, so that the angle between the bucket and the ground remains substantially constant, so objectionable tilting back of the bucket with the consequent spilling of dirt and debris on the tractor and operator is prevented. Also the stroke of the ram required for dumping is less than usual, and during digging or cutting operations the linkage converts the pull on the lever by the bucket to a push on the tilt ram and over the full piston area of the piston. In the dumping operation, the linkage converts the pull on the ram to a push on the bucket, consequently dumping the bucket more quickly since the volume of the cylinder is reduced by the volume of the piston rod.

The invention further consists inthe several features hereinafter described and more particularly defined by claims at the conclusion hereof.

In the drawings:

Fig. 1 is a side elevation view of a loader embodying the invention;

Fig. 2 is a plan view of the loader.

Referring to the drawings, the numeral 3 designates generally a tractor preferably of the crawler type having endless propelling treads or tracks I mounted as usual on sprockets 5 carried by a track frame 6 and which is usually driven from the rear sprocket through suitable transmission mechanism driven from the engine on the body frame I of the tractor.

Each of the track frames 6 has uprights 8 carrying a push beam support 9 to which the push beam I is pivotally mounted by a shaft H extending transversely of the rear of the tractor. The push beams are connected together in front by a tubular frame member l2. Pivotally mounted to hang from the member |2 with a limited amount of swinging movement are ground engaging shoes l3, and pivotally connected to the forward ends of the shoes l3 by pins H are the ears l of a bucket l6.

The arms or push beams l0 are adapted to be raised and lowered by hydraulic means comprising a double acting hydraulic cylinder I for each arm which is pivotally connected at I8 to the 2 support 9, and its ramrod I9 is pivotally connected by a pin 20 to its aim l0.

The above described construction is now known, and this application relates to means associated therewith for tilting and controlling the angle of tilting of the bucket It. For this purpose each push arm or beam has a lever 2| pivotally mounted thereon at P intermediate its ends, the lower end of said lever being operatively connected by a link 22 to the upper portion of the back of the bucket at 23 and the upper end of said lever being pivotally connected by a pin 24 to an extensible link 25 which is pivotally connected by a pin 26 to the support 9, thepivot point 26 being below the pivot shaft II for the push beams. -The extensible link 25 includes a double acting hydraulic cylinder 21, the rod 28 of whose piston is connected by the pin 24 to the lever 2| and whose cylinder is secured to a rod 29 pivoted on the pin 25.

The ends of the hydraulic cylinder have pipes 30 adapted to be connected to any suitable hydraulic system including control valves and a source of pressure fluid whereby pressure fluid is admitted at one end of the cylinder while exhausting from the other end, or pressure fluid introduced at both ends of said cylinder holds the piston in any set position.

With the above arrangement when the push beams III are in the full line position and the bucket It in its lower dotted line position and the tractor moves forwardly, the bucket .|6 cuts into the ground or bank and scoops up its load. Under these digging conditions it will be noted that the digging forces exerted on the cutting edge of the bucket tend to tip it down about he pins l4, thereby exerting a pull on the links 22 which through the lever 2| is converted into a push on the piston rod 28. Inasmuch as thi is the time at which maximum force is exerted on the bucket and also on the ram, it will be seen that the piston is pushing against the base of the ram and against the full area of the piston.

Thereafter the cylinder 21 is operated so as to swing the upper end of the lever 2| forwardly and lower end backwardly, thereby through the link 22 tipping the bucket l6 backwardly to a load carrying position shown in full lines in Fi l in which position it may be skidded while riding on the shoes l3 to a place of deposit.

For dumping the load, the arms or beams ID are raised upwardly by the cylinders to an elevated position, for example, that shown in dotted lines in Fig. 1. During this movement, the extensible link 25 carrying the tilt ram or cylinder 21 the link 22 to tilt the bracket 16 downwardly 1 about its pivots it from its upper dotted line position to discharge the load. In as much as the raising of the load has through the above described linkage already moved the bracket forwardly from its carrying position, it is only necessary for the ram to complete the last half of the swing for dumping, so that the same can be quickly accomplished, more purchase can be had on the bucket when needed, and shorter stroke rams can be used than are customarily employed. Also in as much as the oil enters the front end of the cylinder 21, it needs to displace only the volume of the cylinder minus the volume occupied by the piston rod 28, so that for a constant volume of oil the bucket will move to its dumping position faster than to its carrying position.

We desire it to be understood that this invention is not to be limited to any particular form or arrangement of parts except in so far as such limitations are included in the claims.

What we claim as our invention is:

1. In a loader for use.in a tractor vehicle, the combination of supporting means pivotally mounted on said vehicle, a digging bucket pivotally carried at the outer ends of said supporting means, means for raising and lowering said supporting means, means for tilting said bucket relative to said supporting means comprising a lever carried by said supporting means, a link connecting said lever with the bucket, and an tilting said bucket relative to said push beams comprising a lever pivoted intermediate its ends on apush beam, a link connecting the lower end of said lever with the back of said bucket, and an extensible link connecting the upper end of said lever witha fixed pivot point on a tractor vehicle below the pivotal connection of 'said push beams with said vehicle, and a hydraulic cylinder in said extensible link for extending and contracting the same to vary the digging angle of the bucket and to tilt the bucket to dumping position, that part of said link connected with said lever carrying the piston for said cylinder.'

3. In a loader for use on tractor vehicles, the

combination of a pair of push beams pivotally mounted at their rear ends on said vehicle and projecting forwardly therefrom at their forward ends, a digging bucket pivotally carried at the extensible link connecting said lever with a fixed pivot point on the tractor vehicle below the bucket and to tilt the bucket to dumping position.

2. In a loader for use on a tractor vehicle, the

forward ends of said push beams, means for raising and lowering said push beams, means for tilting said bucket relative to said push beams comprising levers pivoted intermediate their ends on the push beams, links pivotally connecting the lower end of said levers with the back of said bucket, and an extensible link connecting the upper end of each lever with a fixed pivot point on the tractor below the pivotal connection of said push beams, and hydraulic cylinders forming parts of said extensible links for moving said levers to tilt the bucket to dumping position and vary its digging angle, those parts of said links connected with said lever carrying the pistons for said cylinders.

EDWARD A. DROTI. EDWARD R. DRO'I'I'.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,383,686 Ryan Aug. 28, 1945 2,413,097 Barker Dec. 24, 1946 2,427,461 Johnson Sept. 16, 1947 Pokorny Jan. 27, 1948 Certificate of Correction Patent No. 2,482,612

EDWARD A. DROTT ET AL.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows:-

Column 3, line 45, strike out the word hydraulic and insert the same in line 46 before meansflsecond occurrence;

and that the said Letters Patent should be read as corrected above, so that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 20th day of March, A. D. 1951.

THOMAS F. MURPHY,

Assistant Commissioner of Patents.

September 20, 1949 

